(1) Field of the Invention
The present invention relates to a method and an apparatus for simultaneously heating materials by means of laser radiation, with an arbitrary shape of the substantially flat heating contour.
(2) Prior Art
It is known to heat materials by means of laser beams for the purpose of material shaping, for example for welding, soldering, cutting, etc. It is also known to connect plastics to one another by means of laser beams, for example using the laser transmission method. For welding purposes, the laser transmission method by means of IR radiation makes use of the different absorption in the parts to be welded to one another. The upper part, facing the laser source, is transparent to the laser beam, whereas the lower part absorbs the laser beam, and so because of the heating of the lower part the two components fuse at the welding point and are pressed together under pressure. Relatively fine and high-precision welds, in particular of micromechanical components, can be undertaken by means of the laser beam. It is advantageous to undertake the welding over the entire welding line simultaneously so that, during an exposure operation, the entire, substantially flat welding contour is heated and the components are welded to one another. In this way, the air gap between the components can be bridged during welding, and unevennesses can be balanced out.